Precision contraangle piece



, "1,621i90 March 15 1927. R. w. BROWN PRECISION CONTRA ANGLE PIECE Filed April. 19, 1926 9.01 I .v I IV (3' my. /.9.

V INVENTOR, R 7113707072 Patented Mar. 15, 1927..

UNITE RAY w. BROWN,

Pics.

APPLIANCES CO., OF LOS ANGELES, CALIFORNIA.

PRECISION coNrn-AANGLE PIECE.

Application filed April 19, 1926. Serial No. 103,053.

This invention relates to dental hand pieces.

An object of the present invention is to structurally improve dental hand pieces and at the same time secure efficiency in the resultant work with the tool.

Another object is to provide an angle hand piece wherein the driving" gear is positioned in such relative angle to the housing and driven gear therein that I am able to wholly eliminate the usual elbow gears set in the bend of an elbow part attached to the housing and, by my invention, I eliminate said part by disposing the driving pinion in a lateral chamber, of the housing which is at an oblique angle to the axis of the housing and the driven mechanism therein.

- Further, an object is to provide a dental hand piece which can be easily cleaned and kept in a highly sanitary condition.

An additional object is to provide a onepiece main bearing box in whichthe running mechanism has bearing surfaces maintained in true alinement, which is difiicult when the bearings are of separate pieces.

And an object is to secure simplicity and reduction of cost by reduction of number of separable parts.

An important object is to provide astructure of this class wherein the reaction of the work is thrust against a part which cannot untliread as a result of the friction imposed.

Other objects and advantages will be made manifest in the following specification of apparatus embodying a form of the invention; it being understood that modifications, variations and adaptations may be resorted to within the spirit and scope of the invention as it is here claimed.

Figure 1 is a side elevation of a full size, angle hand piece. Figure 2 is a plan of the housing and its cap (about double size, as are all of the remaining views). Figure 3 is an axial section of the hand piece. Figure 4 is an axial section of the separate housing. Figure 5 is an axial section of the housing locking nut. Figure 6 is a plan of the top of the housing nut. Figure 7 is a plan of the top of a barrel element. Figure 8 is a side elevation of the barrel. Figure 9 is an axial section of the barrel. Figure 10 is a plan of a collet box and its attached driven gear. Figure 11 is a sideelevation of the box. Figure 12 is an axial section of the box. Figure 13 is an elevation of the collet. Figure 14 is a'section of the collet.

'Figure 15 is an end View of the collet. Figure 16 is a top plan of the collet jam screw. Figure 17 is an axial section of the jam screw. Figure 18 is a side elevation of the jam. screw. Figure 19 is aside View of a common dental burr. 1 y The present hand pieceis'designedto grip a tool having a stem S with or without a D head D, under-cut at neck N.

The hand piece includes a tubular collet 2 with reversible or duplicate conical ends 8 and having longitudinal slots 4: infrom each end to enable contraction tightly onto the stem S of any adaptable tool. 2 is designed to slide upin a box 5 having The collet a chamber 6 at the inner end of which is I a convergent shoulder 7 to stop the collet and contract. it when a jam screw '23 is screwed into threads'8 in thecha'mber 6.

Fixed firmly on the collet box is a driven gear 10, and at the upper end the collet box has a conical head 9 with acylindrical bear- 1 ing rim. The gear 10 also has a cylindrical bearing body 11. The'waist of the box 5 is reduced or cut away for clearance. as will appear later. The box 5 and gear 10 are a unit having side and end bearings in a barrel '13.,

The barrel has a rounded cap 14 with a narrowfiange 15. In the barrel is a conical seat 16 toreceive the 'head 9 of the box 5 and a bore 17 receives the cylinder of the head 9. The open end of the barrel has an enlarged bore'18 to fit the. gear body 11 for operation with minimum play. Hence the barrel forms an integral element providing all the side bearings for the running box 5 and forms the inner end thrust bearing 16, yvhiph, therefore, cannot work loose under oac.

The barrel'13 has external threads 20 and is bodily. inserted into a housing 21- which is overlapped by the narrow flange 15 of the cap 14 of the barrel. When the barrel left-handthreads) a jam nut 23, having a conical seat 2 1 for the collet 2, is passed through the nut 22 and up into box5. so as is placed in the housing 21 a clamp nut 22 is screwed up on the threads 20 of the barrel. After the nut 22 isrun on (preferably by to jam the collet against the seat 16 and compress the jaws of the collet on the tool stem S when inserted.

If the tool stem has a D head this is received by a D hole 5 in the top of the box.

Extending at a suitable angle from the housing 21 is a lateral chamber 21 to receive the co-ordinate end of a driving means usually including a driving pinion 25 (Fig. 3);

In common forms of contra-angle hand pieces the drive pinion extends into the housing at a 90 angle. This necessitates an extra outer. set of mitered gears in an elbow arrangement to provide the angle in an old and well known manner. A purpose of my present invention is to. dispense with the outer set Oi elbow gears entirely. I do this by disposing the lateral chamber 21 at an. angle of about to the axis of the housing 21, see Figs. 3 and 4. By so doing the drive pinion meshes with the gear 10 at an angle oblique to'its axis. The barrel 13 has a side window 13 for the drive pinion 25 and the waistof the box is red'uced for clearance.

It will be seen that the box 5 can be pulled axially from the barrel, as soon as the retaining nutQtZ has been removed, without disconnecting and removing the drive'means 25 from the lateral chamber 21 which is necessary in all of the common hand-pieces of which I am aware. This is for the reason that the running box has no collar or band overhanging the associated drive pinion; i

hat is claimed is: V

l. A contra-angle hand piece having a housing with a side chamber for a drive means, a barrel inthe housing and having aclosed end provided with an inside, end thrust seat, a driven box journalled in the barrel and bearing endwise against said seat,

a contractive. collet in said box for holding an inserted dental tool, and means attached to said box for-contracting the collet.

2. A contra-angle hand piece having a housing'with a side chamber for a drive means, a barrel in the housing and having a closed end provided with an inside, end

thrust seat, a driven box journalled in the barrel and hearing endwise against said seat, a contractive collet in said box for holding an inserted tool, means engaging the box for contracting the collet, and means for holding the box in the barrel. I

A contra-angle hand piece having a housing with a side chamber for a drive means, a barrel in the housing and having a closed end provided with an inside, end thrust seat, a driven box journalled in the barrel and bearingendwise against said seat, tool holding means in the box, and means for holding the box in the barrel and for clan'iping the barrel in the housing.

at. In a contra-angle hand piece, a fixed one-piece barrel having" an internal closed end thrust seat and cylindrical, coaxial, diti'erential bearing bores, and a running box, for a collet, hearing at one end, against said seat and bearing in said bores.

5. In a contra-angle hand piece, a fixed 'one-piece, closed end barrel having an internal end thrust seat and cylindrical, ditterential bearing bores, a running collet box bearing on said seat and bores, and a collet jamming screw in one end oi" the box.

6. In a dental hand piece, a running collet box having an open bottom end for a collet and provided with an external gear shoulder, a head on the upper end of the box and presenting an internal seat for the collet';

the body of the box being unobstructed above the gear so as to slide into a housing to mesh the gear with its driver.

'7. A contra-angle hand piece having a housing including a lateral chamber, a barrel fitting down inthe housing and having a closed head, a drive extending from said chamber into the barrel, a collet box adjustable into the lower end of the barrel and bearing up against the top of the barrel; said box having on its lower end'a gearto pass up into mesh With the pinion when the box is inserted at the bottom of the housing, means to support the box in place and securing 0n the barrel, a collet in the box, and

means below the last named means to set the collet.

. RAY 1V. BROWN. 

